add postgresql sample project.

samples/Sample.RabbitMQ.PostgreSql/AppDbContext.cs

+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.EntityFrameworkCore;
+
+namespace Sample.RabbitMQ.PostgreSql
+{
+    public class AppDbContext : DbContext
+    {
+        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
+        {
+            optionsBuilder.UseNpgsql("Server=localhost;Database=Sample.RabbitMQ.PostgreSql;UserId=postgre;Password=123123;");
+        }
+    }
+}

samples/Sample.RabbitMQ.PostgreSql/Controllers/ValuesController.cs

+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Threading.Tasks;
+using DotNetCore.CAP;
+using Microsoft.AspNetCore.Mvc;
+
+namespace Sample.RabbitMQ.PostgreSql.Controllers
+{
+    [Route("api/[controller]")]
+    public class ValuesController : Controller
+    {
+        private readonly AppDbContext _dbContext;
+        private readonly ICapPublisher _capBus;
+
+        public ValuesController(AppDbContext dbContext, ICapPublisher capPublisher)
+        {
+            _dbContext = dbContext;
+            _capBus = capPublisher;
+        }
+
+        [Route("~/publish")]
+        public IActionResult PublishMessage()
+        {
+            _capBus.Publish("sample.rabbitmq.mysql", DateTime.Now);
+
+            return Ok();
+        }
+
+
+        [Route("~/publish2")]
+        public IActionResult PublishMessage2()
+        {
+            _capBus.Publish("sample.kafka.sqlserver4", DateTime.Now);
+
+            return Ok();
+        }
+
+        [Route("~/publishWithTrans")]
+        public async Task<IActionResult> PublishMessageWithTransaction()
+        {
+            using (var trans = await _dbContext.Database.BeginTransactionAsync())
+            {
+                await _capBus.PublishAsync("sample.kafka.sqlserver", "");
+                
+                trans.Commit();
+            }
+            return Ok();
+        }
+        
+        [NonAction]
+        [CapSubscribe("sample.rabbitmq.mysql")]
+        public void ReceiveMessage()
+        {
+            Console.WriteLine("[sample.rabbitmq.mysql] message received");
+            Debug.WriteLine("[sample.rabbitmq.mysql] message received");
+        }
+    }
+}

samples/Sample.RabbitMQ.PostgreSql/Program.cs

+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore;
+using Microsoft.AspNetCore.Hosting;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.Logging;
+
+namespace Sample.RabbitMQ.PostgreSql
+{
+    public class Program
+    {
+        public static void Main(string[] args)
+        {
+            BuildWebHost(args).Run();
+        }
+
+        public static IWebHost BuildWebHost(string[] args) =>
+            WebHost.CreateDefaultBuilder(args)
+                .UseStartup<Startup>()
+                .Build();
+    }
+}

samples/Sample.RabbitMQ.PostgreSql/Sample.RabbitMQ.PostgreSql.csproj

+<Project Sdk="Microsoft.NET.Sdk.Web">
+
+  <PropertyGroup>
+    <TargetFramework>netcoreapp2.0</TargetFramework>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.AspNetCore.All" Version="2.0.0" />
+    <PackageReference Include="Npgsql.EntityFrameworkCore.PostgreSQL" Version="2.0.0-preview2-final" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\src\DotNetCore.CAP.PostgreSql\DotNetCore.CAP.PostgreSql.csproj" />
+    <ProjectReference Include="..\..\src\DotNetCore.CAP.RabbitMQ\DotNetCore.CAP.RabbitMQ.csproj" />
+    <ProjectReference Include="..\..\src\DotNetCore.CAP\DotNetCore.CAP.csproj" />
+  </ItemGroup>
+
+</Project>

samples/Sample.RabbitMQ.PostgreSql/Startup.cs

+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+using Microsoft.AspNetCore.Builder;
+using Microsoft.AspNetCore.Hosting;
+using Microsoft.Extensions.Configuration;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+
+namespace Sample.RabbitMQ.PostgreSql
+{
+    public class Startup
+    {
+        // This method gets called by the runtime. Use this method to add services to the container.
+        public void ConfigureServices(IServiceCollection services)
+        {
+            services.AddMvc();
+        }
+
+        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
+        public void Configure(IApplicationBuilder app, IHostingEnvironment env)
+        {
+            app.UseMvc();
+        }
+    }
+}